1. Field of the Invention
The present invention generally relates to connectors used with electronic devices such as computers. More specifically, the present invention relates to connectors used with communications cards that allow computers to be connected to electronic devices and communications systems.
2. Description of Related Art
Portable computers and other electronic equipment frequently use communications cards to allow electrical communication to be established between electronic devices or to allow electronic devices to be connected to communication systems. These communications cards are typically located internally within the computer or electronic equipment and the cards are relatively small in size. The communications cards, for example, are commonly used with modems, fax/modems, Local Area Network (LAN) adaptors and cellular telephone equipment.
Conventional communications cards are often constructed according to the Personal Computer Memory Card International Association (PCMCIA) guidelines, which set forth the physical specifications and electronic architecture of the cards (also known as PC cards). The PCMCIA guidelines define three types of cards and sockets for support of electronic equipment. For instance, PCMCIA standards require all PC cards to have the same length and width (roughly the size of a credit card), and each card includes a connector to allow it to be connected to the computer or other host device. In particular, according to the known PCMCIA standards, PC cards have a length of 85.6 mm (3.4 inches), a width of 54.0 mm (2.1 inches), and a height of 3.3 mm (0.1 inches), 5.0 mm (0.2 inches) or 10.5 mm (0.4 inches) depending upon if the card is a Type I card, Type II card or Type III card, respectively. Type I PC cards are typically used for memory devices such as read only memory (RAM), flash memory or static random access memory (SRAM). Type II PC cards are generally used with input/output (I/O) devices such as data/fax modems, LANs and mass storage devices. Type III PC cards are used for devices whose components are thicker and require additional space. The PCMCIA guidelines also define corresponding types of sockets. Type I sockets support only Type I cards, Type II sockets support Type I and II cards, and Type III sockets support all three types of cards.
A conventional PC card 10 is shown in FIG. 1. The PC card 10 has a generally rectangular shaped body with a top surface 12, a bottom surface 14, a right side 16, a left side 18, a front end 20 and a rear end 22. The terms xe2x80x9cfrontxe2x80x9d and xe2x80x9crearxe2x80x9d are used in reference to the direction in which the PC card 10 is inserted into the receiving socket. The front end 20 of the PC card 10 includes a 68-pin connector 24 that is used to connect the card to an electronic device such as a notebook or lap top computer. Disposed within the PC card 10 is a printed circuit board or substrate 26 with various electronic components 28 that provide the necessary circuitry to perform the intended functions of the PC card.
Additionally, a variety of connectors have been developed in order to facilitate electrical communication between electronic devices and to allow electronic devices to be connected to communication systems. These conventional connectors typically include a plug and a corresponding jack that is sized and shaped to receive the plug. Thus, when the plug is inserted into the jack, the connector allows electrical communication to be established between the plug and the electronic device.
These conventional connectors are frequently constructed according to standards that are well known in the art to promote compatibility and interchangeability. These standard connectors allow various electronic devices and communication systems to be interconnected or linked as desired by the user. For instance, a conventional electrical connector that is well known in the art is the RJ-xx series of connectors, such as the RJ-11, RJ-12 and RJ-45 connectors. The RJ series of connectors include a plug and a corresponding jack that is sized and configured to receive the plug. The RJ-11 connector, for example, includes four or six contact pins and is commonly used to attach communication devices, such as telephones, facsimile machines and modems to electronic devices. The RJ-45 connector includes eight contact pins and it is frequently used to connect LANs or Ethernets to electronic devices. The RJ series of connectors have the same overall configuration except for slightly different widths. Thus, the RJ-11 and RJ-45 connectors have the same general configuration, but the RJ-45 connector is slightly wider than the RJ-11 connector.
As shown in FIGS. 2 and 3, a conventional RJ series connector 30, such as a RJ-11 connector, includes a jack 32 and a plug 34. The plug 34 includes a rectangular contact pin block 36 with a front end 38, a rear end 40, top surface 42, bottom surface 44, and a plurality of contacts 46 located proximate the front end of the block. The contacts 46 are recessed within tracks formed in the contact pin block 36, and the contacts are accessible from the front end 38 and bottom surface 44 of the block. A cable 48 is used to electrically connect the plug 34 to a communications system or other electronic device. The front end 38 of the contact pin block 36 also includes a pair of notches that define front abutment surfaces 50 that are perpendicular to the top surface 42 of the block.
A biased retention clip 52 extends from the top surface 42 of the contact pin block 36. The biased clip 52 includes a broad base 54 in which the front end is integrally attached to the top surface 42 or front end 38 of the block 36, and the other end includes a narrow tab 56 extending away from the base 54. An abrupt transition between the base 54 and the tab 56 creates a pair of retention edges 58 on both sides of the tab 56. The biased clip 52 extends at an angle relative to the top surface 42 of the contact pin block 36 and the biased clip may be elastically deformed towards the top surface of the contact pin block. As best seen in FIG. 2, the jack 32 includes an aperture 60 that is sized and configured to receive the plug 34. In particular, the jack 32 includes a first pair of notches 62 with a first opening 63 disposed between this first pair of notches, and a second pair of notches 64 with a second opening 65 disposed between this second pair of notches. When it is desired to insert the plug 34 into the jack 32, the user depresses the biased clip 52 towards the top surface 42 of the contact pin block 36 and this permits the plug to be inserted into the receptacle. The user then releases the biased clip 52 after it is inserted into the jack 32 and, as shown in FIG. 3, the biased clip 52 returns to its original position. The plug 34 is securely held within the jack 32 because the retention edges 58 of the biased clip 52 engage the inner surfaces of the second pair of notches 64 and the narrow tab 56 extends through the opening 65 formed between the second pair of notches.
The jack 32 includes a plurality of contact pins 66 that elastically deform or deflect as the plug 34 is inserted into the aperture 60. In greater detail, each contact pin 66 includes a wire with a straight section 68 and a contact section 70 that are joined by a bend 72. As shown in phantom in FIG. 3, the wire is bent at an angle xcex1 of at least 120xc2x0 with respect to the straight section 68 when the plug 34 is not inserted into the jack 32. When the plug 34 is inserted into the jack 32, the contact 46 on the plug 34 pushes the contact section 70 of the contact pin 66 downwardly towards the straight section 68 of the contact pin until the contact pin is bent or folded back upon itself at an angle of about 180xc2x0.
Although conventional RJ series connectors are effective in establishing electrical communication between RJ series plugs and RJ series receptacles, these known devices have several drawbacks. For example, repeated insertion and removal of the contact plug from the receptacle produces significant stresses on the contact pins. These stresses may eventually result in failure of the contact pins. In particular, the contact pins have a large stress concentration where the wire is bent back upon itself, and the repeated insertion and removal of the plug often causes this portion of the wire to fail. Additionally, the contact pins can be easily bent beyond their elastic limit and this may also cause the connector to fail.
In order to prevent failure of the contact pins, it is known to make the contact pins thinner or out of a different material to create a tighter radius of curvature. This tighter radius of curvature, however, further increases the stresses at the bent portion of the contact pins. It is also known to construct the contact pins from various materials and then heat-treat the pins for increased strength, but this undesirably increases the costs and complexity of manufacturing. Further, it is also known to decrease the amount of deflection of the contact pins as the plug is inserted into the receptacle, but this often results in insufficient electrical contact between the contact pins and the corresponding contacts in the plug.
The electronic devices used with these conventional RJ series connectors are becoming smaller and smaller. Because these electronic devices are becoming smaller, one or more of the dimensions of the RJ series connector may now be larger than one or more of the dimensions of the electronic device. For example, communications cards that comply with the PCMCIA guidelines have a height that is less than the height of conventional RJ series connector. In particular, communications cards that comply with the PCMCIA standards have a maximum height of 10.5 mm for a Type III PC card, but a conventional RJ-11 jack has a minimum height of at least 12.0 mm. Thus, a conventional RJ-11 jack cannot be mounted in a PC card because the height of the RJ-11 jack exceeds the height limitation of the PC card. As shown in FIG. 4, a known device to connect an RJ series connector to a PC card includes a physical/electrical connector 80 that is integrally attached to the rear end of a PC card 82. The physical/electrical connector 80 includes a generally rectangular shaped body 84 with a conventional RJ series jack or receptacle 86. Disadvantageously, because the physical/electrical connector 80 extends outwardly from the computer 88, the computer may no longer fit within its carrying case, the protruding connector may be easily broken o damaged, the protruding connector may limit the usefulness of the computer, and the connector alters the aesthetics of the computer.
It is also known to use flexible connectors or adaptors to connect RJ series connectors to a communications card. These known adaptors, however, suffer from several drawbacks such as requiring the user to externally carry the adapter from the computer. Thus, the user must remember to bring the adaptor, otherwise the communications card cannot be used. Disadvantageously, users commonly misplace or lose such adaptors. In addition, these known adaptors are typically bulky and that exacerbates the problems associated with externally carrying the adaptor. In addition, these known adaptors typically extend well beyond the periphery of the host computer and that limits the usefulness of the adaptor, and often posed problems when used in tight space confinements.
Other known devices have been developed in order to allow conventional RJ series connectors to be used with PC cards. For example, U.S. Pat. Nos. 5,183,404; 5,335,099; 5,338,210; 5,547,401; 5,727,972 and 5,816,832 disclose assorted devices and methods to connect RJ series connectors to PC cards. These patents are assigned to the same assignee as the present application and are hereby incorporated by reference in their entireties. Briefly, the above-listed patents generally disclose a thin plate that is slidably mounted to a PC card. The thin plate includes a top surface with an aperture formed therein and a plurality of contact wires mounted to the thin plate. Each contact wire includes a first end that is freely exposed within the aperture and a second end that is connected to the thin plate. A flexible wire ribbon is typically used to electrically connect the second end of the contact wires to contacts on a printed circuit board located within the PC card.
As known in the art, the thin plate selectively slides between an extended position and a retracted position. In the extended position, the aperture is exposed such that a corresponding plug, such as a RJ-11 plug, can be inserted and contacts on the plug engage the contact wires extending into the aperture. This allows electrical connection to be established between the plug and the printed circuit board. In particular, electrical communication is established between the plug, contact wires, flexible wire ribbon and printed circuit board. When not in use, the thin plate is retracted into the PC card and the aperture is not exposed. The flexible wire ribbon allows the thin plate to be repeatedly moved between the extended and retracted positions because it freely bends or folds as the plate is moved.
Another known device for using a RJ series connector with a PC card is disclosed in U.S. Pat. No. 5,773,332 issued to Glad. As shown in FIG. 5, the Glad patent discloses a communications card 90 that follows the PCMCIA card Type III standards for dimensions and configuration. The Type III PC card 90 includes two receptacles 92, 94 that are designed to receive standard RJ-xx plugs (specifically, a RJ-11 plug and a RJ-45 plug). The Type III PC card 90 also includes an upper surface 96 and a lower surface 98 that form a portion of the housing of the communications card. The Glad patent explains that because the height of a PCMCIA Type III card is still not great enough to allow standard RJ-xx series receptacle to be mounted therein, T-shaped cutouts 100 are removed from the housing of the communications card 40. The T-shaped cutouts 100 accommodate the biased clip 102 and the ridge 104 present on the connector plug 106. The shape of the T-shaped cutout 100 engages the biased clip 102 and the ridge 104 to hold the plug 106 in place. The Type III PC card height limitation of 10.5 mm, however, is not satisfied when the connector plug is inserted into the receptacle because the biased clip 102 extends through the cutout 100 and protrudes through the upper surface 96 of the housing. Disadvantageously, the biased clip 102 can be easily broken or damaged because it protrudes through the upper surface 96 of the card 90. Further, the protruding clip 102 may limit design options and uses of the communications card because it does not meet the Type III PC card configuration and size requirements.
Still another known device for connecting a RJ series connector to a PC card is disclosed in U.S. Pat. No. 5,984,731 issued to Laity. As shown in FIGS. 6 and 7, a plug 110 is inserted into a receptacle 112 located between upper and lower surfaces 114, 116 of a communications card 118. The receptacle 112 includes a cutout 120 to allow the biased clip 122 of the plug 110 to extend through the outer surface of the communications card 118. Specifically, the Laity patent explains that by providing an open bottom in the receptacle, the retention clip, in the fully inserted position of the modular plug is permitted to project outwardly from the lower, horizontal outer surface of the card. Accordingly, the 10.5 mm height of the Type III card can incorporate a receptacle conforming to the FCC RJ connector standards, but the biased clip of the plug must be allowed to project through the cutout in the outer surface of the card.
Disposed between the upper and lower surfaces 114, 116 of the communications car 110 are contact wires 124 that include a first end 126 soldered to the upper surface of the printed circuit board 128 and a second end 130 that extends into the receptacle 112. As seen in FIG. 6, the contact wires 124 include a first angled section 132 that is bent at a 180xc2x0 angle such that the wire is folded back upon itself and a second angled section 134 that is bent at a 90xc2x0 angle.
As seen in FIG. 7, when the plug 110 is inserted into the receptacle 112, the first angled section 132 and the second angled section 134, along with other portions of the contact wires 124, bend and deform. The bending of the contact wires 124 at these sharply angled sections 132 and 134 creates undesirable stresses in the wires, which may break or deform the wires. Additionally, the Laity patent suffers from the same drawbacks as discussed above in connection with the Glad patent because the biased clip extends through the outer surface of the communications card. Therefore, the potential use and operation of this device is limited because it does not meet the PCMCIA height limitation of 10.5 mm when the plug is inserted into the receptacle. Further, as seen in FIG. 7, when the plug 110 is inserted into the receptacle 112, the contact wires 124 are forced upwardly towards the upper surface 114 of the communications card. Because the contact wires 124 deflect vertically, the receptacle 112 must have sufficient vertical height in order to allow this vertical deflection of the contact pins. That is, because the contact wires 124 deflect vertically, the receptacles must have enough height to allow the deflection of the contact wires 124.
Although these known devices allow electrical communication between RJ series connectors and communications cards to be established, these devices are disadvantageous because the contact wires are prone to damage, wear and being broken. Because the connectors are typically permanently attached to the communications card, this forces the user to dispose of the entire communications card if the connector is broken or damaged. Additionally, if the biased clip of the plug protrudes through an outer surface of the communications card, it is more likely to be broken or damaged. Further, if the biased clip is not completely depressed before the plug is attempted to be removed from the jack, the biased clip may be broken.
A need therefore exists contact pins for a connector jack that eliminates the above-described disadvantages and problems.
One aspect of the present invention is a contact pin design for a low profile modular jack. Preferably, the contact pin design is for a modular jack that has a height of less than 12.0 mm. More preferably, the contact pin design is for a modular jack that is mounted within a PC card and the jack conforms to the Type III PC card height limitation of 10.5 mm. Most preferably, when the plug is received within a receptacle in the modular jack, the plug is entirely contained within the receptacle and no portion of the plug extends through either upper or lower surfaces of the PC card.
Another aspect is a contact pin design for a modular jack that allows the contact pin to deflect a large amount for secure electrical engagement with the corresponding contact in the connector plug. In particular, the contact pin includes a plug engaging portion that provides for a large amount of deflection. Additionally, the plug engaging portion includes an elongated arm that helps absorb stresses and forces caused by the deflection of the pin. Preferably, the elongated arm has a length that is generally equal to or greater that the length of the receptacle. Significantly, the pin is very durable and reliable because the contact pin deflects or flexes along an extended length, not just a small portion of the pin.
Still another aspect is a robust contact pin design that does not include any significant stress concentrations or stress points in the portion of the pin that deflects when the plug is inserted or removed from the receptacle. In particular, the contact pin includes a plug engaging portion that does not include any portions that are angled or curved more than 90xc2x0 in order to reduce stress points and stress concentrations in the contact pins. Preferably, the plug engaging portion includes portions that are angled less than 90xc2x0, such as 60xc2x0, 45xc2x0 or 30xc2x0, in order to further decrease the stresses in the pins. The contact pin also includes a connector portion that is used to connect the pin to a printed circuit board. Desirably, the contact pins are attached to corresponding contacts on the upper surface of the printed circuit board by a card edge connector. The contact pins, however, can also be electrically connected to the printed circuit board by soldering or inserted into through-holes located in the printed circuit board.
A further aspect is a contact pin that includes significant horizontal deflection of the pin when the plug is inserted into the receptacle. Preferably, the deflection of the contact pin includes a horizontal component that is larger than the vertical component of the deflection. Significantly, because a portion of the pin is deflected horizontally, the pin requires less vertical deflection and that decreases the required vertical height of the receptacle. Thus, the contact pin facilitates manufacturing of a low profile modular jack.
Yet another aspect is a contact pin in which the front end of the pin is located proximate the front end of the receptacle. This front end of the contact pin may be either fixed or slidably disposed within groove in the lower surface of the receptacle. If the contact pins are fixed within the grooves, the pins may be constructed by insert or injection molding.
Further aspects, features and advantages of the present invention will become apparent from the detailed description of the preferred embodiments that follows.